Hair clipping device

Abstract

The present invention relates to a hair clipping device, comprising: a housing; a cutting assembly (12) which is arranged on one end of said housing and comprises a stationary blade (14) and a moveable blade (16) that is resiliently biased against the stationary blade (14), wherein the stationary blade (14) and the moveable blade (16) define a cutting plane (30) between each other, wherein the stationary blade (14) comprises a first recess (34) and the moveable blade (16) comprises a second recess (32), wherein the first and the second recess (34, 32) are arranged on top of each other; a motor (18) for driving an eccentric transmission element (26); and a coupling element (28) coupled to said eccentric transmission element (26) for translating a movement of said eccentric transmission element (26) into an oscillatory movement of the moveable blade (16) relative to the stationary blade (14); wherein said eccentric transmission element (26) engages the coupling element (28) at at least one engagement point (38), wherein said at least one engagement point (38) is in at least one operating position during the movement of said eccentric transmission element (26) within said cutting plane (30), and wherein the coupling element (28) is arranged in said first and second recess (34, 32).

Claims

1. Hair clipping device, comprising: a housing; a cutting assembly which is arranged on one end of said housing and comprises a stationary blade and a moveable blade that is resiliently biased against the stationary blade by a spring comprising two spring levers, wherein the stationary blade and the moveable blade define a cutting plane between each other, an eccentric transmission element including an eccentric pin protruding therefrom and arranged on a rotary driven shaft, a motor comprising said rotary driven shaft for driving said eccentric transmission element; and a coupling element coupled to said eccentric transmission element for translating a movement of said eccentric transmission element into an oscillatory movement of the moveable blade relative to the stationary blade; wherein the coupling element is arranged inside of a common recess formed from a first rectangular recess in the moveable blade and a second rectangular recess in the stationary blade that form said common recess in the movable blade and the stationary blade; wherein said eccentric transmission element engages the coupling element at at least one engagement point in the same plane as the cutting plane, wherein said at least one engagement point is in at least one operating position during the movement of said eccentric transmission element within said cutting plane, and wherein the coupling element is arranged in said first and second recess, wherein the coupling element is displaced at a spatially low position of the at least one engagement point, where the eccentric transmission element engages the coupling element, and wherein said engagement of said eccentric transmission element engaging said coupling element is within a contacting plane along which the movable blade and the stationary blade contact each other.

2. Hair clipping device according to claim 1, wherein a lower part of said eccentric transmission element is in at least one operating position during the movement of said eccentric transmission element tangent to said cutting plane or spatially crosses said cutting plane.

3. Hair clipping device according to claim 1, wherein the eccentric transmission element is clamped into the coupling element between at least two engagement points, wherein said at least two engagement points are in at least one operating position during the movement of said eccentric transmission element within said cutting plane.

4. Hair clipping device according to claim 1, wherein the coupling element is fitted into the first and second recess to form a positive locking between said coupling element and said first and second recess.

5. Hair clipping device according to claim 1, wherein the first and second recess protrude substantially parallel to a cutting edge of said moveable blade.

6. Hair clipping device according to claim 1, further comprising at least one first ball bearing which is arranged between the moveable blade and the stationary blade.

7. Hair clipping device according to claim 6, wherein said at least one first ball bearing is arranged between two semicircular guiding recesses formed in the moveable blade and the stationary blade, respectively.

8. Hair clipping device according to claim 6, wherein said at least one first ball bearing is coupled to the coupling element.

9. Hair clipping device according to claim 6, further comprising at least one second ball bearing which is arranged between the moveable blade and the stationary blade, wherein the at least one first ball bearing and the at least one second ball bearing are arranged on different sides of said first and second recess of the moveable blade and the stationary blade.

10. Hair clipping device according to claim 6, wherein the centre of the at least one first ball bearing and/or the centre of the at least one second ball bearing is arranged within the cutting plane.

11. Cutting assembly for use in a hair clipping device 1, comprising: a stationary blade; a moveable blade that is resiliently biased against the stationary blade, wherein the stationary blade and the moveable blade define a cutting plane between each other, wherein a common recess is formed from a first rectangular recess in the moveable blade and a second rectangular recess in the stationary blade that collectively form a common recess in the moveable blade and the stationary blade; and a coupling element that is arranged in the common recess coupled to a rotatory driven eccentric transmission element and adapted to translate a movement of said eccentric transmission element into an oscillatory movement of the moveable blade relative to the stationary blade, wherein said coupling element further comprises an engagement part having at least one engagement point at which said eccentric transmission element can engage the coupling element; wherein said eccentric transmission element engages the coupling element at said at least one engagement point in the same plane as the cutting plane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. In the following drawings

(2) FIG. 1 shows a schematical drawing illustrating the arrangement of a driving bridge on a movable blade according to the prior art;

(3) FIG. 2 shows a sectional view of an embodiment of the hair clipping device according to the present invention;

(4) FIG. 3 shows a perspective sectional view of the embodiment shown in FIG. 2 of the hair clipping device according to the present invention;

(5) FIG. 4 shows a top view of the embodiment shown in FIG. 2 of the hair clipping device according to the present invention;

(6) FIG. 5 shows a perspective view of the embodiment shown in FIG. 2 of the hair clipping device according to the present invention;

(7) FIG. 6 shows a frontal view of the embodiment shown in FIG. 2 of the hair clipping device according to the present invention;

(8) FIG. 7 shows an enlarged view of a part of the hair clipping device according to the present invention illustrated in FIG. 6;

(9) FIG. 8 shows a detail of a second embodiment of the hair clipping device according to the present invention;

(10) FIG. 9 shows a detail of a third embodiment of the hair clipping device according to the present invention;

(11) FIG. 10 shows an enlarged view of a further embodiment of a ball bearing that may be used in the hair clipping device according to the present invention, wherein the ball bearing is in a first position;

(12) FIG. 11 shows an enlarged view of the ball bearing shown in FIG. 10, wherein the ball bearing is in a second position; and

(13) FIG. 12 shows a sectional view of a further embodiment of the hair clipping device according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(14) FIGS. 2 to 6 schematically illustrate the principle design of a hair clipping device according to the present invention which is therein in its entirety denoted with reference numeral 10. FIGS. 2 and 3 show sectional views of the hair clipping device 10 and FIGS. 4 to 6 show the hair clipping device 10 from different sides. FIG. 2 therein refers to the sectional view A-A (see FIG. 4) and FIG. 6 refers to the sectional view B-B (see FIG. 4).

(15) The hair clipping device 10 according to the present invention usually comprises a housing (not explicitly shown) in which all remaining parts are usually integrated and which serves as a holder for a cutting assembly 12. The housing usually has an elongated body, wherein the cutting assembly 12 is releasably fixed to a front end of said housing. The housing usually further comprises a handle at its rear end (not shown). The outer surface of the elongated housing may, for example, be tapered outwardly from the rear end to the front end and may have a slightly bent development to provide a more ergonomic holding position and to improve the esthetic appearance of the clipping device 10. However, it is to be noted that also other housing arrangements and designs are envisaged without leaving the scope of the invention.

(16) The cutting blade assembly 12 includes a stationary blade 14 and a movable blade 16. The movable blade 16 is displaceably mounted on an upper surface of the stationary blade 16, which upper surface faces substantially towards the inner side of the housing. By the help of a spring 17 that comprises two spring levers 17, 17 the movable blade 16 is pressed onto the stationary blade 14 in order to keep the two blades close together. The movable blade 16 may comprise a toothed edge 22 with an array of teeth that is arranged substantially parallel to a front edge 23 of the stationary blade 14. Instead of a toothed edge 22 the front edge of the movable blade may also be designed as a sharp continuous edge as this is illustrated in FIGS. 2 to 5. During operation hair cutting is performed due to the interaction of the stationary blade 14 and the movable blade 16 that reciprocates on the stationary blade 14 as this is known from other conventional hair clipping devices.

(17) The stationary blade 14 is usually designed to be thicker than the movable blade 16. Said stationary blade 14 is also denoted as guard. Similar as the front edge 22 of the movable blade 16, the front edge 23 of the guard 14 may either be designed as a sharp continuous edge or as a toothed edge with an array of cutting teeth. In order to receive a good cutting performance, the movable blade 16 is actively pressed to the upper surface of the guard 14 to receive a so-called teeth pressure. This teeth pressure is, inter alia, guaranteed by the above-mentioned spring 17 that presses the two blades 14, 16 together.

(18) A drive arrangement including a motor 18 is adapted to drive the movable blade 16 in an oscillatory movement in a transverse direction 20 parallel to a front cutting edge 22 of the movable blade 16. The motor 18 thereto comprises a rotatory driven shaft 24 that is forced into rotation. An eccentric transmission element 26 including an eccentric pin 27 protruding therefrom is arranged on said rotatory driven shaft 24. The eccentric transmission element 26 may be clamped onto the rotatory driven shaft 24 or coupled to it in any other way. However, the rotatory driven shaft 24 and the eccentric transmission element 26 may also be realized as one integrated part. The motor 18 itself may, for example, be realized as an electric motor that is either powered by main supplied electricity or battery-driven.

(19) The rotatory movement of the eccentric translation element 26 is translated into the translatory movement of the movable blade 16 via a coupling element 28. The coupling element 28 is usually also called driving bridge 28. The coupling element or driving bridge 28 is usually realized as a plastic part. However, also other materials may be generally used for the coupling element 28.

(20) One of the central points of the present invention relates to the arrangement of the coupling element 28 as well as to the arrangement of the eccentric transmission element 26 relative thereto. In contrast to state of the art hair clipping devices, where said driving bridge 28 is mounted on the top surface of the movable blade 16 (compare driving bridge 101 shown in FIG. 1a), the driving bridge 28 is according to the present invention integrated into the cutting assembly 12. Compared to the state of the art, the driving bridge 28 is therefore arranged at a spatially lower position with respect to the cutting assembly 12. Also different as in prior art devices and even more important is the spatial arrangement of the eccentric transmission element 26. Said eccentric transmission element 26 is also arranged at a spatially lower position as in prior art hair clipping devices.

(21) According to the present invention, said eccentric transmission element 26 engages the coupling element 28 at a position that lies in the cutting level 30. The cutting level 30, which is also referred to as cutting plane 30, defines the imaginary plane between the stationary blade 14 and the movable blade 16 along which both blades 14, 16 contact each other.

(22) In order to guarantee such a low arrangement of the coupling element 28 and the engagement of the eccentric transmission element 26 with the coupling element 28, the coupling element/driving bridge 28 is arranged in a first recess 32 and a second recess 34 that form a common recess in the movable blade 16 and the stationary blade 14. The first recess 32 is a recess within the movable blade 16 that preferably has a rectangular shape. The second recess 34 is a congruent recess in the stationary blade 14, which may have the same shape and size as the first recess 32. Together, these two recesses 32, 34 build an inclusion within the cutting assembly 12 for receiving said coupling element/driving bridge 28. Therefore, the coupling element 28 is no longer arranged above the cutting plane/cutting level 30 (as in the prior art) but arranged within the cutting level 30.

(23) The eccentric transmission element 26 engages the coupling element 28 at at least one engagement point. This at least one engagement point is chosen such that it lies in at least one operating position during the movement of the eccentric transmission element 26 in the cutting plane 30. Preferably, said at least one engagement point is during the whole movement of said eccentric transmission element 26 (not only in at least one operating position) within the cutting plan 30.

(24) Such an arrangement reduces the mechanical lever (distance between engagement point and cutting level 30) to zero or almost zero and thus reduces the risk of occurring overturning torques that may lead to a tilt of the movable blade 16. Such a tilt of the movable blade 16 is also known as pulling effect which significantly decreases the hair cutting performance and may lead to a pulling-in of hair into the cutting assembly 12 instead of cutting the hairs with the blades 14, 16. This is, of course, unpleasant for the user as a pulling-in of hair may hurt a lot.

(25) Arranging the engagement of the eccentric transmission element 26 with the coupling element/driving bridge 28 within the cutting plane 30 leads to the fact that the transmission forces for driving the movable blade 16 are transmitted within the cutting level 30 in an overturning torque-free manner.

(26) FIG. 7 shows the engagement of the eccentric transmission element 26 with the coupling element 28 in an enlarged view. The engagement is shown therein in a most preferred position. According to the present invention it is most preferred that the eccentric transmission element engages the coupling element 28 with its eccentric pin 27 at at least one engagement point 38, 38, wherein said at least one engagement point 38, 38 is in at least one operating position during the movement of the eccentric transmission element 26 arranged within the cutting plane 30. Preferably, said at least one engagement point 38, 38 is in during the whole movement of the eccentric transmission element 26 arranged within the cutting plane 30. In that way force will be only transmitted within the cutting level 30. As it can be further seen from FIG. 7, the eccentric pin 27 is preferably clamped into a V-shaped recess within the coupling element 28. It contacts the coupling element 28 at two engagement points 38, 38. The intersection connecting the two engagement points 38, 38 may also be denoted as engagement line. Due to the above-mentioned arrangement, which is also shown in the accompanying drawings, said engaging line, in other words falls together with the cutting plane 30 during the whole movement of the eccentric transmission element 26. Preferably, they do not only fall together in at least one operating position, but during the whole movement of said eccentric transmission element 26. The reason why this is mentioned herein is that the coupling element 28 could be slightly lifted during the rotation of the eccentric pin 27. However, due to the V-shaped recess in the coupling element 28 this relatively small lifting movement of the coupling element/driving bridge 28 may be balanced or even suppressed, so that the engagement points 38, 38 are during the complete movement of the eccentric transmission element 26 arranged within the cutting plane 30.

(27) As it can be seen from FIGS. 2 and 3 the guard 14 furthermore comprises an additional recess 40 that is mainly foreseen to provide enough space for the movement of the eccentric pin 27 in order to prevent collisions.

(28) In summary, the engagement of the eccentric transmission element 26 with the driving bridge 28 is herein designed to be at a spatially lower position compared to known cutting units, in which always an overturning torque is possible that leads to the redoubtable pulling effect. However, due to the herein proposed arrangement this pulling effect may not occur in the clipping device 10 according to the present invention.

(29) A further advantage of the hair clipping device 10 according to the present invention becomes apparent from the arrangement of the coupling element/driving bridge 28 within the recesses 32, 34. The recesses 32, 34 act as a sliding guide for the driving bridge 28. Since the driving bridge 28 is fitted into the recesses 32, 34 by a positive locking, a movement of the movable blade 16 relative to the stationary blade 14 (guard) perpendicular to the transverse direction 20 is limited. The driving bridge 28 accordingly limits the movement of the movable blade 16 and keeps the so-called tip-to-tip distance, i.e. the distance between the front edge 22 of the movable blade to the front edge 23 of the stationary blade, constant during the movement of the movable blade 16. This is especially advantageous, since the tip-to-tip distance becomes never too small so that a user may be hurt by the movable cutting blade 16, and on the other hand never becomes too big, which then could impede the cutting performance (no function because no piece in functional cutting condition). A further positive effect is that the driving bridge 28 is held in the recesses 32, 34 like in a steel frame. In this way, the creep behaviour of the plastic material from which the driving bridge 28 is manufactured, is limited. Therefore, the tolerance of the driving bridge 28 is more constant than in conventional cutting units, which do not have a driving bridge bordered in a metal frame.

(30) All over all, this reduces friction between the driving bridge 28 and the eccentric pin 26 and reduces power consumption as well as it minimizes the noise level of the clipping device 10.

(31) A further central point of the present invention relates to the guidance of the movable blade 16 on the stationary blade 14. Compared to state of the art clipping devices, in which the movable blades usually glide over the stationary blades so that gliding friction is produced therein between, the hair clipping device 10 according to the present invention comprises a ball bearing 42 between the movable blade 16 and the stationary blade 14 in order to establish a rolling friction between these two blades 14, 16.

(32) As friction forces accompanied with rolling friction are only 3% from the corresponding friction forces accompanied with gliding friction, the friction between the movable and the stationary blade 14, 16 is significantly reduced according to the present invention. Besides abrasion, this also significantly reduces the noise level of the clipping device 10. Apart from that, less driving force is lost due to friction so that smaller electric motors may be applied or higher cutting speeds may be reached with the same electric motors.

(33) FIGS. 8 and 9 schematically show the arrangement of the at least one ball bearing 42. In one embodiment illustrated in FIG. 8, two ball bearings 42, 42 are provided on the teeth averted rear side of the cutting unit 12. The balls 43, 43 of the ball bearings 42, 42 are guided in a semicircular guiding recess 44 formed into the movable blade and a corresponding semicircular guiding recess formed parallel thereto into the stationary blade (not explicitly shown). The guiding recess 44 in other words has a shape of a half-pipe. As it can be furthermore seen from FIG. 8, the two ball bearings 42, 42 are coupled to the coupling element 28 in order to guide the ball bearings 42, 42 during the reciprocal movement of the movable cutting blade 16. The semicircular recess 44 is preferably arranged substantially parallel to the front edge 22 of the movable blade 16.

(34) In a different embodiment illustrated in FIG. 9, three ball bearings 42, 42, 42 are provided. One ball bearing 42 arranged on the teeth averted rear side of the cutting unit 12 and the other two ball bearings 42, 42 arranged on the other side of the coupling element 28 and guided in a further semicircular recess 44. This arrangement realizes a statically determinate design, which leads to a maximum stability during the reciprocal movement of the movable cutting blade 16.

(35) It is to be noted that also other variations and arrangements of the ball bearings 42 are possible. The position as well as the number of ball bearings may be varied and adapted to the specific needs.

(36) Instead of semicircular guiding recesses 44 for the ball bearings 42, 42, the recesses 44 may also have a rectangular shape as illustrated in FIGS. 10 and 11. Rectangular recesses 44, compared to semicircular recesses 44, provide an increased resistance against the lifting effect. By comparing FIG. 10 with FIG. 11 it can be seen that the ball 43 of the ball bearing 42 may not slip out of the rectangular recesses 44 in case the moveable blade 16 is slightly displaced relative to the stationary blade 14. Whereas this might lead the ball 43 to slip out of a semicircular guiding recess, this may be prevented with a rectangular recess 44. Therefore, the unwanted lifting effect may not occur at any time.

(37) An additional element for preventing the lifting effect is shown in FIG. 12. FIG. 12 shows a hook element 46 that is arranged above the moveable cutting blade 16. This hook element 46 is adapted to press the moveable cutting blade 16 with contact pressure against the stationary cutting blade (in addition to the spring element 17). A lifting of the moveable cutting blade 16 is thereby prevented.

(38) In summary, the present invention provides a hair clipping device which effectively overcomes the problem of an unwanted pulling of the movable cutting blade. Due to the special technical design that is chosen in the presented hair clipping device, the hair clipping device is especially in terms of cutting performance, force transmission effectiveness, friction, wear and tear as well as in terms of noise level significantly improved.

(39) While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

(40) In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

(41) A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

(42) Any reference signs in the claims should not be construed as limiting the scope.